Why humans have computers, and chimps are stuck with sticks

New research shows that several aspects of social cognition allow humans to …

Humankind has made great conceptual and technological advances since we first walked the Earth. Thanks to our ability to build on others' ideas, we've progressed from the abacus to the computer, from the wheel to the modern-day car, and from simple observations about the world to our current knowledge of the laws of nature and the Universe. This ability to accumulate knowledge and improve on it, referred to as "cumulative culture," is unique to humans.

But what is it about humans that predisposes us to cumulative culture? Some claim that this "ratcheting" of ideas is a result of a particular cognitive ability, such as language or prosociality, that is unique to—or especially prevalent in—humans. Others believe that some social aspect of other species, such as the tendency to scrounge, may preclude them from building on each others' ideas as we can. A new study in Science this week suggests that a few different traits may actually be responsible for our success with cumulative culture.

The researchers used three species in their experiments: chimpanzees, capuchin monkeys, and humans (specifically human children, to minimize the impact of culture). The idea was to compare humans with two closely related species that have cultural traditions, but not cumulative culture itself.

The studies employed a puzzle box that required three consecutive actions to fully open. The idea was to measure how well groups of each species performed on a task with sequential steps, which mirrors the cumulative acquisition of knowledge. In the first step, the subjects had to slide a door open to reveal a somewhat desirable treat. Then, they needed to press a button that let the door slide further and allowed access to a more desirable treat. Finally, in the third stage, they had to turn a dial to slide the door the rest of the way, revealing a really desirable treat. For the chimps and the capuchins, the rewards were carrots, apples and grapes; for the human children, the treats were various types of stickers.

While each group was working with the box, the researchers watched for instances from a set of specific behaviors. They then correlated the frequency of each behavior with how far that species got with the box. Behaviors that were common in groups that progressed through the most stages are likely the same ones that promote cumulative culture.

After 53 hours with the puzzle box, just one capuchin monkey had reached the second stage, and none figured out the third stage. Chimpanzees fared only slightly better: just one figured out stage three, and only four more had reached stage two. As expected, there wasn't any evidence that these species are capable of cumulative culture. Meanwhile, after just 2.5 hours of exposure to the puzzle box, more than sixty percent of the 3- and 4-year old children had figured out stage three.

So what distinguished the humans’ performance from that of the other primates? The researchers found that several behaviors seemed to make the difference, both in terms of which species progressed the furthest, and which individuals within each species did the best.

Only in the human groups did the researchers witness teaching behavior, either through language ("push that button") or gesturing. Furthermore, the children who received the most instruction were more likely to make it to the third stage. The researchers also found that "matching"—when an individual who picks up the box imitates what the last individual using it did—had a great impact on progress. One of the significant measures of prosociality was how often more than one individual manipulated the box simultaneously; these instances can be interpreted as cooperation or, at the very least, tolerance. Humans worked on the box together much more often than either the chimps or the capuchins.

There was no evidence that nonsocial cognition or any aspect of social structure, such as scrounging or social hierarchy, affected performance.

Although there wasn't a quantitative measure, the researchers noted that the humans tended to approach the box in a very different way than either the capuchins or the chimpanzees. The children used the box together, helping each other and sharing the rewards; meanwhile, the other primate species seemed to interact only with the box simply to procure resources.

There are obviously some shortcomings in this research; the experiments took place under artificial conditions, and the "ratcheting" of each idea had to occur over a very short time scale. However, it does give us an idea of the traits that are likely to contribute to cumulative culture on a much larger—and more difficult to study—scale.

I have often watched Nature and noticed the jobs parents do in wildlife situations; however, you very rarely see some form of sharing and teaching by the siblings. The cooperative efforts of humans makes us different and successful no matter what captain of industry claims they did it all by themselves.

When reading this, I kept thinking, well it's making humans sound so special.

Let's be clear. We are not special. There were other primate species that could do this, but we as a species decided that they were mostly not worth mating with and facilitated or actively participated in their genocide. We're not unique, we're just the last ones standing (quasi-pun).

When reading this, I kept thinking, well it's making humans sound so special.

Let's be clear. We are not special. There were other primate species that could do this, but we as a species decided that they were mostly not worth mating with and facilitated or actively participated in their genocide. We're not unique, we're just the last ones standing (quasi-pun).

[Edit: Related my comment to the reading.]

I, for one, would have welcomed our genocided, unmateworthy underlords.

When reading this, I kept thinking, well it's making humans sound so special.

Let's be clear. We are not special. There were other primate species that could do this, but we as a species decided that they were mostly not worth mating with and facilitated or actively participated in their genocide. We're not unique, we're just the last ones standing (quasi-pun).

[Edit: Related my comment to the reading.]

But wouldn't the fact that we're the last ones left make us more unique? Aside from that you're really arguing minutiae. Even if there were 3 human species still around the fact that we'd all be closely related (and thus capable of interbreeding) would still mean we're unique. We are alone among the primates today (at least that we're aware of) in that we build upon each others ideas. Are you arguing against that?

"Thanks to our ability to build on others' ideas, we've progressed from the abacus to the computer, from the wheel to the modern-day car, and from simple observations about the world to our current knowledge of the laws of nature and the Universe."

How do you minimise culture in children do you get them to forget every expectation they have of reality based upon the culture in which they grew up. They could of at least got the researchers to use an animal or unknown lanuage so all the test subjects shared an unfamiliarity with what was being asked.

When reading this, I kept thinking, well it's making humans sound so special.

Let's be clear. We are not special. There were other primate species that could do this, but we as a species decided that they were mostly not worth mating with and facilitated or actively participated in their genocide. We're not unique, we're just the last ones standing (quasi-pun).

[Edit: Related my comment to the reading.]

I, for one, would have welcomed our genocided, unmateworthy underlords.

Well let's hope that cats get prosociality. We could all use some RL furries in our lives.

When reading this, I kept thinking, well it's making humans sound so special.

Let's be clear. We are not special. There were other primate species that could do this, but we as a species decided that they were mostly not worth mating with and facilitated or actively participated in their genocide. We're not unique, we're just the last ones standing (quasi-pun).

[Edit: Related my comment to the reading.]

You seem to be applying a notion of "last" that's somewhat incompatible with how time functions.

When reading this, I kept thinking, well it's making humans sound so special.

Let's be clear. We are not special. There were other primate species that could do this, but we as a species decided that they were mostly not worth mating with and facilitated or actively participated in their genocide. We're not unique, we're just the last ones standing (quasi-pun).

[Edit: Related my comment to the reading.]

I, for one, would have welcomed our genocided, unmateworthy underlords.

How do you minimise culture in children do you get them to forget every expectation they have of reality based upon the culture in which they grew up. They could of at least got the researchers to use an animal or unknown lanuage so all the test subjects shared an unfamiliarity with what was being asked. I would say that this test shows chimps are able to do a test devised by humans but that the opposite would likely not be the case as a human would be too heavy for the branch.

My two-year-old son already knows that when presented with something he's going to push everything that remotely looks like a button, pull and twist anything that might move, and shake it until something fun happens. This is because essentially every baby toy in existence rewards the child for executing just such exploratory actions (jack-in-the-box anyone?).

I wouldn't get too worked up over the concept then that only the humans regularly got to stage 3 - we've been trained from birth to keep manipulating objects for better and better rewards. Perhaps they should have used monkeys that had been raised from birth with these same children's toys that they had to manipulate through multiple stages to feed themselves.

This does not diminish the observations about cooperative actions and the importance of communication.

"Humankind has made great conceptual and technological advances since we first walked the Earth. Thanks to our ability to build on others' ideas, we've progressed from the abacus to the computer, from the wheel to the modern-day car, and from simple observations about the world to our current knowledge of the laws of nature and the Universe."

My two-year-old son already knows that when presented with something he's going to push everything that remotely looks like a button, pull and twist anything that might move, and shake it until something fun happens. This is because essentially every baby toy in existence rewards the child for executing just such exploratory actions (jack-in-the-box anyone?).

I wouldn't get too worked up over the concept then that only the humans regularly got to stage 3 - we've been trained from birth to keep manipulating objects for better and better rewards. Perhaps they should have used monkeys that had been raised from birth with these same children's toys that they had to manipulate through multiple stages to feed themselves.

This does not diminish the observations about cooperative actions and the importance of communication.

Agree with what you're saying re: how these actions are already familiar to human children. I will say however that cooperation is also something that is taught to children (through playing together and sharing toys/food, and to talk things over and not fight) from a young age so they've also got a slight advantage in that sense.

On the other hand, you can't hold that against the human children because it's something they've been taught by their parents and/or society in the same way it could have been taught to the chimps if those things had any value to them.

That chimpanzee looks very frustrated.I'd guess that he's unhappy because he won't be able to install OS X Mountain Lion on his white Macbook.He's trying to figure out if he can afford a new Macbook Pro.

<blockquote> One of the significant measures of prosociality was how often more than one individual manipulated the box simultaneously; these instances can be interpreted as cooperation or, at the very least, tolerance</blockquote>

So is the take-home from this supposed to be that Steve Jobs was a half-evolved monkey man?

[EDIT: I will remove the visible HTML tags when Ars makes it clear what kind of markup is allowed].

Take a look out of the window and say that again. Humans are amazing. Chimpanzees have learned how to use sticks to get at ants. We have been to the freaking moon and millions of humans shuttle at near the speed of sound between continents. And we have figured out most of these things in around 100 years. Pretty good I would say. Even the terrible things are impressive. We could blow the planet up if we wanted to (at least the top layer), we will be the first species since algaes came into existence to change the climate, not responsible perhaps but definitive impressive.

Humans are amazing. We may not always be nice but that's a different topic. I hugely prefer orcas to bunnies. The former may sometimes be cruel but they seem to have the ability to choose between being mean and nice. Similar to humans. Much more interesting.

<blockquote> One of the significant measures of prosociality was how often more than one individual manipulated the box simultaneously; these instances can be interpreted as cooperation or, at the very least, tolerance</blockquote>

So is the take-home from this supposed to be that Steve Jobs was a half-evolved monkey man?

[EDIT: I will remove the visible HTML tags when Ars makes it clear what kind of markup is allowed].

um, "bracket quote bracket". If you hit "reply" on someone else's post it'll quote them and you can see the special super-secret syntax for yourself.

Take a look out of the window and say that again. Humans are amazing. Chimpanzees have learned how to use sticks to get at ants. We have been to the freaking moon and millions of humans shuttle at near the speed of sound between continents. And we have figured out most of these things in around 100 years. Pretty good I would say. Even the terrible things are impressive. We could blow the planet up if we wanted to (at least the top layer), we will be the first species since algaes came into existence to change the climate, not responsible perhaps but definitive impressive.

Humans are amazing. We may not always be nice but that's a different topic. I hugely prefer orcas to bunnies. The former may sometimes be cruel but they seem to have the ability to choose between being mean and nice. Similar to humans. Much more interesting.

*Applause*

It's nice to see that there's someone else who looks around and occasionally thinks "The world is just awesome".

I wouldn't get too worked up over the concept then that only the humans regularly got to stage 3 - we've been trained from birth to keep manipulating objects for better and better rewards. Perhaps they should have used monkeys that had been raised from birth with these same children's toys that they had to manipulate through multiple stages to feed themselves.

This does not diminish the observations about cooperative actions and the importance of communication.

But trained monkeys will behave differently from regular monkeys, so using them changes the parameters of the test. They have great untapped potential though, trained gorillas can learn human sign language and simple ideographs, but basically it never happens in the wild.

When reading this, I kept thinking, well it's making humans sound so special.

Let's be clear. We are not special. There were other primate species that could do this, but we as a species decided that they were mostly not worth mating with and facilitated or actively participated in their genocide. We're not unique, we're just the last ones standing (quasi-pun).

[Edit: Related my comment to the reading.]

Actually the idea that we killed off all of those closely related non-humans is losing acceptance. the evidence is shifting the idea that those other forms of human-like life weren't murdered, but that we are basically the result of different human-likes fucking...

I am probably not explain this well. To be more clear, there was less murdering and more fucking.

Take a look out of the window and say that again. Humans are amazing. Chimpanzees have learned how to use sticks to get at ants. We have been to the freaking moon and millions of humans shuttle at near the speed of sound between continents. And we have figured out most of these things in around 100 years. Pretty good I would say. Even the terrible things are impressive. We could blow the planet up if we wanted to (at least the top layer), we will be the first species since algaes came into existence to change the climate, not responsible perhaps but definitive impressive.

Humans are amazing. We may not always be nice but that's a different topic. I hugely prefer orcas to bunnies. The former may sometimes be cruel but they seem to have the ability to choose between being mean and nice. Similar to humans. Much more interesting.

*Applause*

It's nice to see that there's someone else who looks around and occasionally thinks "The world is just awesome".

Boomdeyada

Hey now, I'm constantly appreciative of all the wonders that my social species has come up with. I give thanks nearly every day that when I want fresh water I press a button and it comes out of a fountain. I'm even more grateful considering that my access to said fresh water is unfortunately a function of where I was born, and not my being human.

What I'm saying is we were probably not the only ones to ever develop cumulative culture. Perhaps my mistake is using special interchangeably with unique.

If you feel special for being human, that's awesome. We're special. Feel good about all the amazing things we can do. There's a reflective dish on the moon that you can shoot a laser at just so that you can time the length of the trip there and back to confirm the distance of the moon. We're awesome.

If you feel humans are unique for having cumulative culture, I'm saying, hold up, the jury is still out on that.

Too bad that with some companies greed and need to patent troll and sue everybody under the sun, people will think twice about improving upon other concepts and ideas for fear of being sued into bankrutpcy and labeled "thieves" by morons.

Kate Shaw Yoshida / Kate is a science writer for Ars Technica. She recently earned a dual Ph.D. in Zoology and Ecology, Evolutionary Biology and Behavior from Michigan State University, studying the social behavior of wild spotted hyenas.